Drugs of abuse are associated with a variety of cognitive deficits including disruption of learning and memory. Animal models are needed to better assess the cognitive risks of use and abuse of psychoactive drugs. However, procedures available to study memory in rodents are generally limited to the study of retention of a single stimulus or place across a delay interval. The goal of the proposed research is to elaborate a recently developed test that assesses rodent's ability to remember an increasing number of odors within a single experimental session: the olfactory span task. This procedure offers the novel potential to analyze the effects of drugs as a function of memory load. Aim 1 experiments will determine the acute effects of drugs of abuse and other selected compounds that are thought to have amnestic effects on olfactory memory using the span procedure including benzodiazepines (chlordiazepoxide, midazolam), NMDA antagonists (dizocilpine, ketamine), opiates (morphine), psychostimulants (methylphenidate, methamphetamine, MDMA), and an anticholinergic hallucinogen (scopolamine). The Aim 2 experiments will examine residual effects on memory span after exposure to neurotoxic doses of MDMA and methamphetamine that have been associated with amnestic effects in humans and in some animal models. An overarching goal of the project is to develop and evaluate this new methodology as a tool in the assessment of the effects of drugs on memory. Finally, the proposed research will provide an ideal opportunity for students to develop skills and background in psychopharmacology and neuroscience. PUBLIC HEALTH RELEVANCE: Drugs of abuse may produce cognitive deficits and this project will develop a new animal model to identify and characterize acute and residual effects of abused drugs on memory capacity.